Laboratory-scale waste stabilisation pond development.

The present study describes the development of a laboratory-scale waste stabilisation pond (WSP) system, undertaken in order to investigate the effects of hydraulic, physicochemical, microbial and physical parameters on wastewater treatment. Previous studies have focused predominantly on hydraulic characteristics. This system was engineered at a scale much smaller than had previously been seen in the literature.

Outcomes of the first combined national survey of pesticides and emerging organic contaminants (EOCs) in groundwater in New Zealand 2018.

The first national survey of Emerging Organic Contaminants (EOCs) involved sampling 121 wells located throughout New Zealand and analysis for a suite of 29 EOCs. This survey was carried out in conjunction with the 2018 national survey of pesticides in groundwater, a survey that is conducted on a four-yearly basis which included the analysis of glyphosate for first time. A total of 227 EOCs were detected in the 85 wells (70%).

Use of Sonication for Enhanced Sampling of Attached Microbes from Groundwater Systems.

The vast majority of microorganisms in aquifers live as biofilms on sediment surfaces, which presents significant challenges for sampling as only the suspended microbes will be sampled through normal pumping. The use of a down-well low frequency sonicator has been suggested as a method of detaching microbes from the biofilm and allowing rapid sampling of this community. We developed a portable, easy to use, low-frequency electric sonicator and evaluated its performance for a range of well depths (tested up to 42 m below ground level) and casing types.

The effects of denitrification parameterization and potential benefits of spatially targeted regulation for the reduction of N-discharges from agriculture.

Diffuse nitrate leaching from agricultural areas is a major environmental problem in many parts of the world. Understanding where in a catchment nitrate is removed is key for designing effective land use management strategies that protect water quality, while minimizing the impact on economic development. In this study we assess the effects of spatially targeted nitrate leaching regulation in a basin with limited knowledge of the complexity of chemical heterogeneity.

Efficacy of Coral Sand for Removal of and Bacteriophage under Saturated Flow Conditions.

Knowledge of how effectively microbes are transported through porous media is useful for water resource/wastewater management. Despite much research having been done to characterize microbial contaminant transport through various sedimentary materials, very little study has been made on coral sand, such as constitutes the primary substrate of many Pacific atolls. We conducted a set of laboratory column experiments as a preliminary examination of how effective coral sand is at attenuating model pathogens J6-2 and MS2 bacteriophage (phage) under saturated flow conditions mildly representative of field conditions at the Bonriki freshwater lens, South Tarawa, Kiribati.